One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6,9,11)(7,10,12,8)(13,14,16,19)(15,18,21,26)(17,20,24,27)(22,28,23,25)(1,2,4,3)(5,7)(6,10)(8,11)(9,12)(13,15,16,21)(14,18,19,26)(17,22,24,23)(20,28,27,25)(6,11)(7,12)(14,19)(15,21)(20,27)(22,23) involution — undirected(5,8,9,10)(6,12,11,7)(14,19)(15,22)(17,24)(18,25)(21,23)(26,28)(1,3,4,2)(15,21)(18,26)(22,23)(25,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.